Methods of making heat exchangers

ABSTRACT

A method of making a heat exchanger of the kind comprising a stack of sheet metal pressings in face to face relation, adjacent pairs of pressings providing between them alternately channels for flow of coolant and spaces for the flow of air, the method consisting of cold welding the pressings together.

United States Patent Duke et al.

[451 Nov. 7, 1972 [54] METHODS OF MAKING HEAT EXCHANGERS [72] Inventors:Anthony John Duke, Stoke; Horace John Dagley, Rugby, both of England 1Assignw Chry yni st sfins lmlim tsds.

England [22] Filed: March 16,1970

[21] Appl. No.: 19,777

[30] Foreign Application Priority Data March 20, 1969 Great Britain..14,744/69 [52] US. Cl. ..29/157.3 D, 29/157.3 B, 29/470.1, 113/118 R,113/118 D [51] Int. Cl. ....B2ld 53/00, B21k 29/00, B23p 15/26 [58]Field of Search....29/l57.3 R, 157.3 D, 157.3 B, 29/470.1; 113/118 R,118 D; 165/166, 167

[56] 9 References Cited UNITED STATES PATENTS 2,790,628 Barnes..29/470.l X

2,821,772 2/ 1958 Billetter ..29/470.1 X 2,874,942 2/1959 Rieppel et a1..29/470.1 X 3,071,216 1/1963 Jones et al. ..29/470.1 X 1,954,638 4/1934Loeffler ..-......29/157.3 1,990,752 2/1935 Ragsdale ..l13/118 D X2,617,634 11/1952 Jendrassik ..165/140 3,451,114 6/1969 Werneke..29/157.3 3,512,238 5/1970 Canon et a1 ..113/118 X 3,537,165 11/1970Paddock et al....l13/118DX FOREIGN PATENTS OR APPLICATIONS 1,007,886 10/1965 Great Britain Primary Examiner-John F. Campbell AssistantExaminer-Victor A. DiPalma Attorney-Mawhinney & Mawhinney [57] ABSTRACTA method of making a heat exchanger of the kind comprising a stack ofsheet metal pressings in face to face relation, adjacent pairs ofpressings providing between them alternately channels for flow ofcoolant and spaces for the flow of air, the method consisting of coldwelding the pressings together.

6 Claims, 8 Drawing Figures METHODS OF MAKING HEAT EXCHANGERS Thisinvention relates to methods of making heat exchangers for'example foruse in the coolant systems of internal combustion engines.

The invention provides a method of making a heat exchanger of the kindcomprising a stack of sheet metal pressings in face to face relation,adjacent pairs of pressings providing between them alternately channelsfor flow of coolant and spaces for the flow of air, which methodcomprises joining pairs of pressings which provide between them spacesfor flow of air by cold welding and then joining the thus formed pairsof cold welding to provide the channels for flow of coolant.

The cold welding of each pair of pressings and of the pairs of pressingsmay be carried out in a number of cold welding operations at adjacentlocations.

The cold welding operations may be carried out at overlapping locations.

A fin or fins may be secured to the pressings in each air space.

Prior to the cold welding of the pressings to form pairs, a fin of waveor zig-zag form may be welded at alternate crests to the side of eachpressing which bounds an air space.

The crests of the fins may be cold welded to the pressing.

The fins may be located on the pressings so that crests on the fins ofadjacent pressings abut one another.

In the case where each pressing has two spaced depressions havingopenings in the bottom thereof, a channel connecting the two depressionsand a peripheral flange extending along either side of the channel andaround the depressions, pairs of pressings may first be assembled withthe spaced depressions of one pressing inengagement with the spaceddepressions of another pressing, the engaging depressions are coldwelded together and the resulting pairs of pressings are assembled withtheir flanges in engagement and then the flanges are cold weldedtogether.

The following is a description of a specific embodiment of a radiatorfor a motor vehicle constructed in accordance with the inventionreference beingmade to the accompanying diagrammatic drawings in which:

FIG. 1 is a side view of part of one of the pressings which makes up theradiator;

FIG. 2 shows the pressing with finning applied to one side:

FIG. 3 is a side view of two pressings and a tool for securing thepressings together;

FIG. 4 is an enlarged view of part of the tool for securing thepressings together;

FIG. 5 is a plan view of the assembly shown in FIG. 3;

FIG. 6 is a side view of two of the assemblies shown in FIG. 3 and atool for securing them together;

FIG. 7 shows a pattern of welds which may be used, using a tool such asthat of FIG. 6; and

FIG. 8 shows a further pattern of welds which may be used.

end and a channel 14 extends along the pressing between the depressions.

Referring now to FIG. 2 of the drawings finning formed by bending a thinstrip 16 of aluminium into wave formation is cold welded along thespaced crests on one side of the strip to the outside of the channel 14of the sheet 10 between the depressions 12.

As shown in FIG. 3 of the drawings two of the pressings 10 are offeredup together with the spaced depressions 12 on one of the sheets inengagement with the spaced depressions 12 on the other sheets. Theengaging parts of the depressions around the openings 13 are then coldwelded together by a tool comprising upper and lower dies 17 and 18. Thedie 18, as shown in FIG. 4, is formed with a projecting ring 19 on itsupper surface and the die 17 is formed with a similar projecting ring 20on its lower surface. The lower die 18 is introduced through the openside of the depression 12 in the lower pressing and the upper die 17 isintroduced through the open end of the depression 12 in the upperpressing and the dies are brought together with sufficient force to coldweld the engaged parts of the depressions trapped between the ring 19and the ring 20 together. The engaging depressions at both ends of thepressings are welded together in this manner. The bottoms of thechannels 14 of the resulting assembly are spaced apart to permit flow ofair between them.

The finning formed by the bent strip 16 is located on the two pressingsso that the crests on one of the strips which are spaced from thepressing abut the crests of the other strip which are spaced from thepressing to which the other strip is secured.

Two of the assemblies thus formed are then offered up together withtheir flanges 11 (see FIG. 5) in face to face relationship and theflanges 1 1 are cold welded together by the tool illustrated in FIG. 6of the drawings which comprises upper and lower dies 21 and 22 whichhave oppositely projecting rims 23, 24. A length of the abutting flangesto be cold welded together is introduced between the rims on the dies21, 22 as shown in FIG. 6 and a load is applied to the upper die 21sufficient to effect cold welding of the flanges. A further length ofthe flanges is introduced between the dies and is cold welded and thisis repeated until the entire peripheries of the flanges have been coldwelded. Preferably the flanges are welded together at overlappinglocations. In a modified method, illustrated in FIG. 7, the flanges 11are first welded along the full lines 30 and then along the broken lines31 to fonn a continuous weld. Alternatively the end parts of the flangesmay be welded as shown in FIG. 8 using a modified form of the tool shownin FIG. 6 which forms U-shaped weld lines as indicated at 32, theremaining parts of the flanges being welded by a tool of the type thestack form header tanks to which supply and return conduits areconnected. The channels 14 form communicating passages for flow ofcoolant between the two headers and cooling air passes between thespaced bottoms of the channels.

We claim:

l. A method of making'a heat exchanger of the kind nel thereof withcertain crests of the wavesabutting the channel and the remaining.crests spaced from the channel;

secondly internally supporting the channel;

c. thirdly applying pressure to those crests abutting the channel tocold weld the crests to the channel and at the same time to form groovesin the channel which receive said crests; i

. fourthly assembling pairs of the pressings together with thedepressions of adjacent pressings in engagement with one another andsaid remaining crests of the fins of the pressings in engagement withone another;

e. fifthly cold welding said depressions together;

f. sixthly assembling the resulting pairs in face to face relation withthe peripheral flange of one pressing abutting the peripheral flange ofanother pressing; and I finally .-cold welding the peripheral flanges.

together.

2. A method as claimed in claim 1 wherein the cold welding of each pairof depressions and of each pair of abutting peripheral flanges. iscarried out in a series of cold welding operations at adjacentlocations.

. 3a-A method as claimed in claim 1 wherein the cold welding of eachpair of depressions and of each pair of peripheral flanges is carriedout in a series of cold welding operations at overlapping locations. v

4. A method as claimed in claim 1 wherein the fins are located on thepressings so that crests on the fins of adjacent pressings of each pairabut one another.

5. A method as claimed in claim 1 wherein step (e) of claim 1 isperformed in two cold welding operations comprising cold weldingportions of the flanges together and then cold welding the remainingportions of the flanges together to form a continuous weld.

6. A method as claimed in claim 1 wherein step (e) of claim 1 isperformed in two cold welding operations comprising cold welding the endparts of the flanges together to form U-shaped weld lines and coldwelding the remaining parts of the flanges together to form a continuousweld.

1. A method of making a heat exchanger of the kind comprising a stack ofsheet aluminum or aluminum alloy pressings in Face to face relation,each pressing having two spaced depressions each provided with anopening in the bottom thereof, a channel connecting the depressions anda peripheral flange, which method comprises the steps of: a. firstlylocating fins of wave form having spaced crests on each pressing on theoutside of the channel thereof with certain crests of the waves abuttingthe channel and the remaining crests spaced from the channel; b.secondly internally supporting the channel; c. thirdly applying pressureto those crests abutting the channel to cold weld the crests to thechannel and at the same time to form grooves in the channel whichreceive said crests; d. fourthly assembling pairs of the pressingstogether with the depressions of adjacent pressings in engagement withone another and said remaining crests of the fins of the pressings inengagement with one another; e. fifthly cold welding said depressionstogether; f. sixthly assembling the resulting pairs in face to facerelation with the peripheral flange of one pressing abutting theperipheral flange of another pressing; and g. finally cold welding theperipheral flanges together.
 2. A method as claimed in claim 1 whereinthe cold welding of each pair of depressions and of each pair ofabutting peripheral flanges is carried out in a series of cold weldingoperations at adjacent locations.
 3. A method as claimed in claim 1wherein the cold welding of each pair of depressions and of each pair ofperipheral flanges is carried out in a series of cold welding operationsat overlapping locations.
 4. A method as claimed in claim 1 wherein thefins are located on the pressings so that crests on the fins of adjacentpressings of each pair abut one another.
 5. A method as claimed in claim1 wherein step (e) of claim 1 is performed in two cold weldingoperations comprising cold welding portions of the flanges together andthen cold welding the remaining portions of the flanges together to forma continuous weld.
 6. A method as claimed in claim 1 wherein step (e) ofclaim 1 is performed in two cold welding operations comprising coldwelding the end parts of the flanges together to form U-shaped weldlines and cold welding the remaining parts of the flanges together toform a continuous weld.